Passive optical networks are becoming prevalent in part because service providers want to deliver high bandwidth communication capabilities to customers. Passive optical networks are a desirable choice for delivering high-speed communication data because they may not employ active electronic devices, such as amplifiers and repeaters, between a central office and a subscriber termination. The absence of active electronic devices may decrease network complexity and/or cost and may increase network reliability.
FIG. 1 illustrates a network 100 deploying passive fiber optic lines. As shown, the network 100 can include a central office 110 that connects a number of end subscribers 115 (also called end users 115 herein) in a network. The central office 110 can additionally connect to a larger network such as the Internet (not shown) and a public switched telephone network (PSTN). The network 100 also can include fiber distribution hubs (FDHs) 130 having one or more optical splitters (e.g., 1-to-8 splitters, 1-to-16 splitters, or 1-to-32 splitters) that output a number of individual fibers that may lead to the premises of an end user 115. The various lines of the network can be aerial or housed within underground conduits.
The portion of the network 100 that is closest to the central office 110 is generally referred to as the F1 region, where F1 is the “feeder fiber” from the central office. The F1 portion of the network may include a distribution cable 120 having on the order of 12 to 48 fibers; however, alternative implementations can include fewer or more fibers. The portion of the network 100 that includes an FDH 130 and a number of end users 115 can be referred to as an F2 portion of the network 100. The network 100 includes one or more break-out locations 125 at which branch cables are separated out from main cable lines. Branch cables are often connected to drop terminals 104 that include connector interfaces for facilitating coupling the fibers of the branch cables to a plurality of different subscriber locations.
Splitters used in an FDH 130 can accept a feeder cable having a number of fibers and may split those incoming fibers into, for example, 216 to 432 individual distribution fibers that may be associated with a like number of end user locations. In typical applications, an optical splitter is provided prepackaged in an optical splitter module housing and provided with splitter output pigtails that extend from the module. The splitter output pigtails are typically connectorized with, for example, SC, LC, or LX.5 connectors. The optical splitter module provides protective packaging for the optical splitter components in the housing and thus provides for easy handling for otherwise fragile splitter components. This modular approach allows optical splitter modules to be added incrementally to FDHs 130 as required.
The FDHs 130 may be provided in outdoor or indoor environments. For example, some FDHs 130 may be mounted on pedestals or posts outdoors. Other FDHs 130, however, are installed in compact spaces in which room may be limited. For example, an FDH 130 may be mounted within a closet or other enclosed space in which a bulky cabinet can be detrimental. Accordingly, an FDH 130 having reduced dimensions may be beneficial.